Mark each of the following true or false. 

___ a. Every normal series is also subnormal. 

___ b. Every subnormal series is also normal. 

___ c. Every principal series is a composition series. 

___ d. Every composition series is a principal series. 

___ e. Every abelian group has exactly one composition series. 

___ f. Every finite group has a composition series. 

___ g. A group is solvable if and only if it has a composition series with simple factor groups. 

__ h. S₇ is a solvable group. 

___ i. The Jordan-Holder theorem has some similarity with the Fundamental Theorem of Arithmetic, which states that every positive integer greater than 1 can be factored into a product of primes uniquely up to order. 

___ j. Every finite group of prime order is solvable.